VD OFDMDemod

Demodulator for OFDM Signals

Virtual Devices are the basic building blocks for a modern IT-based COMINT solution.

OFDMDemod

Signal Input

- IF Signal

Signal Output

- Symbols

Parameter

- Center Frequency

-

Frequency Mode

-

OFDM Mode

Result Parameter

- Locked

-

Locked Status

-

Baud rate

-

Frequency Offset

-

Bit SNR

-

Symbol SNR

-

Mirror

General

The VD “OFDMDemod” demodulates OFDM (Orthogonal Frequency Division Multiplex) signals. The demodulated signal is output in the form of a symbol stream.

The demodulator is designed for particular requirements of non- cooperative reception (listen mode).

Properties of the VD

The center- or carrier frequency of the input signal for demodulation can be input as an absolute or relative value.

The VD can demodulate mirrored input signals.

Definition of the multi-faceted settings for the OFDM parameter setting is done at the factory and s upplied as a configuration file. MIL-188-110-A forms part of the standard device and therefore no further OFDM-specific parameter setting is required on the VD.

OFDM MIL-188-110A

Technical data

Modulation

PSK2, PSK4, PSK8, PSK16 differentially

Number of channels

8 – 200 @ df = variably

Baud Rate

Variably

Center frequency

Adjustable, AFC range +/- 3 x dF Hz

TX Modus

Continuous

Bit error rate (BER) (MIL-188-110A configuration)

< 5.0 x 10 -4@ Eb/N0 = 9 dB < 3.5 x 10 -5@ Eb/N0 = 10 dB

Output

- Demodulated symbols

Status Information (Locked, Ch0, SNR, Freq.Offset)

-

-

-

-

- Intel ®

-

AMD ®

VD-DE-OFDM

Real-time factor approx. 60, measured with:

Windows XP®, CPU AMD Athlon® XP2800+

Sampling rate 4.8 kHz @ MIL-188-110A OFDM

- Windows 2000®, XP®, Vista®

Linux Suse 9.0 / 9.2 / 9.3 ®

Computing power

The computing power required depends on the sampling rate of the input signal as well as the operating system and CPU.